docs: def create_from_file_extension(cls, file_extension):
          """
          Create a table writer class instance from a file extension.
          Supported file extensions are as follows:
  
              ==================  ===================================
              Extension           Writer Class
              ==================  ===================================
              ``".csv"``          :py:class:`~.CsvTableWriter`
              ``".htm"``          :py:class:`~.HtmlTableWriter`
              ``".html"``         :py:class:`~.HtmlTableWriter`
              ``".js"``           :py:class:`~.JavaScriptTableWriter`
              ``".json"``         :py:class:`~.JsonTableWriter`
              ``".jsonl"``        :py:class:`~.JsonLinesTableWriter`
              ``".ltsv"``         :py:class:`~.LtsvTableWriter`
              ``".ldjson"``       :py:class:`~.JsonLinesTableWriter`
              ``".md"``           :py:class:`~.MarkdownTableWriter`
              ``".ndjson"``       :py:class:`~.JsonLinesTableWriter`
              ``".py"``           :py:class:`~.PythonCodeTableWriter`
              ``".rst"``          :py:class:`~.RstGridTableWriter`
              ``".tsv"``          :py:class:`~.TsvTableWriter`
              ``".xls"``          :py:class:`~.ExcelXlsTableWriter`
              ``".xlsx"``         :py:class:`~.ExcelXlsxTableWriter`
              ``".sqlite"``       :py:class:`~.SqliteTableWriter`
              ``".sqlite3"``      :py:class:`~.SqliteTableWriter`
              ``".tsv"``          :py:class:`~.TsvTableWriter`
              ``".toml"``         :py:class:`~.TomlTableWriter`
              ==================  ===================================
  
          :param str file_extension:
              File extension string (case insensitive).
          :return:
              Writer instance that coincides with the ``file_extension``.
          :rtype:
              :py:class:`~pytablewriter.writer._table_writer.TableWriterInterface`
          :raises pytablewriter.WriterNotFoundError:
              |WriterNotFoundError_desc| the file extension.
          """
  
          ext = os.path.splitext(file_extension)[1]
          if typepy.is_null_string(ext):
              file_extension = file_extension
          else:
              file_extension = ext
  
          file_extension = file_extension.lstrip(".").lower()
  
          for table_format in TableFormat:
              if file_extension not in table_format.file_extensions:
                  continue
  
              if table_format.format_attribute & FormatAttr.SECONDARY_EXT:
                  continue
  
              return table_format.writer_class()
  
          raise WriterNotFoundError(
              "\n".join(
                  [
                      "{:s} (unknown file extension).".format(file_extension),
                      "",
                      "acceptable file extensions are: {}.".format(", ".join(cls.get_extensions())),
                  ]
              )
          )